• Step 1: Preheat your oven to 375°F (190°C). Grease a 9×13-inch baking dish and set it aside.
• Step 2: Cook the penne pasta according to the package instructions until al dente. Drain and set aside.
• Step 3: In a large skillet, heat the olive oil over medium-high heat. Add the cubed chicken and garlic, and sauté until the chicken is cooked through, about 6-8 minutes. Remove the chicken and garlic from the skillet and set aside.
• Step 4: In the same skillet, sauté the diced onion until translucent, about 5 minutes.
• Step 5: Add the cream cheese, Parmesan, mozzarella, and heavy cream to the skillet. Stir until the cheeses are melted and the sauce is smooth and creamy.
• Step 6: Add the cooked pasta and chicken back to the skillet, and stir to combine. Season with Italian seasoning, salt, and pepper to taste.
• Step 7: Transfer the mixture to the prepared baking dish and smooth the top.
• Step 8: Bake for 20-25 minutes, or until the top is golden brown and bubbly.